Truckmixer



y 21, 1957 c. F. MITTELSTADT ETAL 2,793,013

TRUCKMIXER IS Sheets-Sheet 1 Filed 001:. 7, 1953 lilil?! r INVENTOR.

CLARENCE F. "ITTELSTADT HARRY C. PETERS llfld MAURICE P. BALDY BY THE IR ATTORNEY May 21, 1957 Filed Oct. 7, 1953 C. F. MITTELSTADT ETAL TRUCKMIXER 3 Sheets-Sheet 2 INVENTOR. CLARENCE F. MITTELSTADT, HARRY C. PETERS and MAURICE P. BALDY w n w THEIR ATTORNEY y 1957 c. F. MITTELSTADT ETAL 2,793,013

TRUCKMIXER Filed Oct. 7, 1953 3 Sheets-Sheet 5 INVENTOR. CLARENCE F. IIITTELSTADT HARRY C. PETERS and MAURICE P BALDY gla gwu/vw THEIR A TORNEY United States Patent 0 TRUCKMIXER Clarence F. Mittelstadt, Wexford, and Harry C. Peters and Maurice P. Baldy, Pittsburgh, Pa., assignors to Blaw-Knox Company, Pittsburgh, Pa., a corporation of Delaware Application October 7, 1953, Serial No. 384,594

10 Claims. (Cl. 259-168) This invention relates to truckmixers, such, for example, as truckrnixers for concrete. It relates to mixers of the type having a mixing drum, water tank and engine mounted on a carrier which is movable from place to place. The carrier may take various forms but for purposes of explanation and illustration will be deemed to be a truck chassis.

The art of truckmixers is well developed. For years it has been customary to mount on a carrier such as a truck chassis a truckmixer assembly consisting of a supporting frame, a mixing drum together with means for rotating the drum, :1 water tank and means for pumping water from the water tank into the mixing drum. The water pumped from the water tank into the mixing drum may be employed either as a component of the mix or to flush out the mixing drum. When the water is employed as a component of the mix it may be metered and an automatic shutoff provided for stopping the how of water after a predetermined quantity of water has been pumped into the mixing drum as well known to those skilled in the art.

The mixing drum of a truckmixer may be mounted on the frame for rotation about an axis extending generally longitudinally of the frame and the carrier. The drum may have an open end for receiving the ingredients and discharging the mixture and may be closed at its opposite end. The so-called high-discharge type of truckmixer is arranged with the drum having its open end facing rearwardly of the truck and with the drums axis inclined to the horizontal so that the oen end is at a higher elevation than the closed end. Such a mixing drum may be mounted for rotation by a journal and bearing at the closed end and supporting rollers intermediate the ends of the drum but normally closer to the open end than to the closed end.

It has been customary to support the closed end of high-discharge mixing drums on a bearing pedestal at the forward end of the frame, or just behind the cab of the truck when the frame is mounted upon a truck chassis. it has been customary to mount the driving unit or engine for the mixing drum on the frame in front of the pedestal and to mount the water tank above the driving unit and pedestal. The mixing drum has normally been mounted concentrically of the carrier from side to side, i. e., so that its axis and the longitudinal axis of the carrier have been disposed in the same vertical plane. Such a structure had disadvantages which have long been recognized but not obviated prior to our invention. The driving unit or engine for operating the mixing drum was enclosed on five of its six sides and was relatively inaccessible. The elevated water tank, especially when full, made the center of gravity of the structure quite high with the result that the portable mixer was eatively top-heavy, requiring great care to avoid its tipping over when traversing rough terrain. In some models the top of the elevated water tank was the highest point of the portable mixer and increased its headroom requirements. The mechanical parts such as the transmission, clutches, drive for the water pump, etc., were "ice compressed into a small space and rendered ditficultly accessible for maintenance and repair and not convenient for operation. The loaded mixing drum also was laterally out of balance relatively to the carrier since the material being mixed tends during rotation of the mixing drum to dispose itself eccentrically of the mixing drum in the direction of the side of the mixing drum which moves generally upwardly. Moreover, the desired longitudinal mass distribution was interfered with by the positioning of the driving unit at the forward end of the frame. Such mounting of the driving unit prevented mounting of the mixing drum as far forward on the carrier as is desirable. When the truckmixer, mounted on a truck chassis, is full of material the load on the front wheels ahead of the cab is always below the permissible wheel loads for streets and highways, but the load on the rear wheels of the truck approaches or may exceed the legal load limit, particularly for the larger sizes of truckmixers. The mass of the mixing drum is much greater than the mass of any other element of the structure and it is important that the center of gravity of the mixing drum be as far forward on the carrier as possible so that a larger portion of the total load is carried by the front Wheels of the motor truck and a smaller portion of the total load is carried by the rear wheels of the truck.

We have obviated all of the above mentioned disadvantages by an entirely new truckmixer having the elements arranged differently than heretofore with important advantages in operation, maintenance, balance and economy of space. We lower the water tank to the deck of the frame and mount it directly thereon, and dispose the forward bearing, for the closed end of the mixer, above the water tank. We preferably dispose the mixing drum slightly eccentrically of the carrier in the direction of the side of the mixing drum which moves generally downwardly when the mixing drum is being rotated about its axis so that the center of gravity of the mixing drum together with the material being mixed therein lies approximately over the longitudinal axis of the carrier. We preferably dispose the driving unit or engine on the deck of the frame laterally of the mixing drum, desirably at the rearward end of the carrier. We preferably dispose the transmission adjacent one end of the water tank, in the clear space at one side of the carrier, and drive the transmission and water pump from the engine by a longitudinal drive shaft disposed beside the mixing drum.

We find it of great advantage to dispose the bearing for the mixing drum which is at the closed end of the mixing drum above the top of the water tank so that the axis of the mixing drum at its closed end extends over the top of the tank. We preferably provide means within the confines of the tank supporting the hearing. If the tank itself is of sufficiently rugged construction the bearing may simply be mounted atop the tank as in effect a portion of the tank structure, but normally the tank will be of relatively light construction not capable of supporting the closed end of the mixing drum, in which case we desirably mount the bearing for the closed end of the mixing drum upon a pedestal support constructed within the confines of the tank. The pedestal may be structurally independent of the tank or may serve as strengthening or reinforcing means for the tank. The top plate of the water tank may form a portion of the pedestal which carries the bearing for the closed end of the mixing drum.

The driving unit may be mounted on the frame beside the mixing drum at the rearward end thereof where the drum narrows and the transmission and pump may be mounted on the frame beside the mixing drum at the forward end thereof where the drum narrows. The driving unit, transmission. pump and drive shaft are all in readily accessible locations at one side of the carrier.

The mounting of the driving unit at the rearward portion of the frame leaves free the space previously occupied by the driving unit at the forward portion of the frame which prevented the mounting of the mixing drum as far forward on the carrier as desirable for reasons above explained. We can now locate the mixing drum a substantial distance forwardly on the carrier whereby greatly improved longitudinal mass distribution is realized. the excessive or undesirably high wheel load on the rear wheels of the carrier being substantially reduced and the lower wheel load at the front of the carrier being desirably increased.

Other details. objects and advantages of the invention will become apparent as the following description of a present preferred embodiment thereof proceeds.

In the accompanying drawings we have shown a present preferred embodiment of the invention in which- Figure l is a side elevational view with portions cut away of a truckmixer;

Figure 2 is an end elevational view of the truckmixer shown in Figure l as viewed from its forward end; and

Figure 3 is an end elevational view of the truckmixer shown in Figures 1 and 2 as viewed from its rearward end.

Referring now more particularly to the drawings, there is shown a frame designated generally by reference numeral 2 having Z-bar stringers 2a adapted for mount ing upon the bed or chassis of an automobile truck. The frame 2 may be of generally rectangular shape elongated in the direction of movement of the truck. In Figure l the cab of the carrier would be to the left adjacent the end of the frame 2.

Mounted directly upon the frame 2 at the forward end thereof is a water tank 3 having a filling opening 4. Disposed largely within the confines of the tank 3 is a pedestal 5 which is mounted over the stringers 2a of the frame. The upper end of the pedestal merges with the top of the tank 3 where it carries a bearing 6 rotatably carrying and supporting the forward closed end of a mixing drum 7. The axis of the drum 7 is inclined upwardly away from the tank 3 and the side of the water tank facing the drum is inclined forwardly on the frame whereby the closed end of the drum overlies the side of the tank permitting the drum to be located much closer to the forward end of the frame than was heretofore possible The mixing drum 7 and the means for rotatably supporting it include a journal extending into the hearing 6. and may he conventional except that it is not conventional for the pedestal 5 supporting the bearing 6 for the forward closed end of the mixing drum 7 to be disposed largely within the confines of the tank 3, or, indeed. for the tank 3 to be located where we have located it. Cooperating with the bearing 6 and rotatably supporting the mixing drum 7 are rollers 8 rotatably carried by brackets 9 mounted in a frame 10 forming part of the frame 2.

During rotation of the mixing drum 7 with material therein the material tends to dispose itself eccentrically of the mixing drum in the direction of the side of the mixing drum which moves generally upwardly. Viewing Figure 2. the mixing drum 7 rotates in the counterclockwise direction as indicated by the arrow 11. Consequently. the material Within the drum tends to dispose itself eccentricully of the drum. more of such material being at the right-hand side of the drum than at the left-hand side thereof viewing Figure 2. The result of this is a shifting of the center of gravity of the drum and material combined to the right, viewing Figure 2, of the axis of the drum. We mount the drum slightly eccentrically of the longitudinal center line of the Z-bars 2a to the left viewing Figure 2 so that the center of gravity of Lit) the drum and contents when the drum is rotated will be approximately over the longitudinal axis of the carrier. In Figure 2 the vertical plane of the drum axis is indicated at 12 and the vertical plane of the longitudinal axis of the carrier (midway between the stringers 2a) is indicated at 13.

Not only does the eccentric mounting of the mixing drum have the advantage of bringing the center of gravity of the mixing drum and contents closer to the longitudinal axis of the carrier but additional space is provided on the carrier at the side thereof away from which the mixing drum is disposed. For every inch the mixing drum is moved toward the left relatively to the longitudinal axis of the carrier, viewing Figure 2, there will be two inches more width at the right-hand side of the carrier clear of the drum than at the left-hand side of the carrier clear of the drum. That additional width at the right-hand side of the carrier viewing Figure 2 makes it possible to mount elements of the mechanism directly upon the carrier alongside the drum which could not previously have been so mounted without undesirably increasing the width of the carrier. Indeed, in anticipation of the mounting of elements of the mechanism at the right-hand side of the carrier, viewing Figure 2, we may so dispose the mixing drum that the center of gravity of the mixing drum and contents during rotation of the mixing drum is to the left of the longitudinal axis of the carrier so that the center of gravity of all of the elements carried by the carrier including the contents of the drum when the drum is rotating may be approximately over the longitudinal axis of the carrier.

Mounted upon the frame 2 at the rearward end thereof and at the one side thereof is the driving unit or engine 14. The engine may per se be of conventional construction. The output shaft 15 of the engine 14 is coupled by a universal coupling 16 to a drive shaft 17 which extends forwardly from the engine to a universal coupling 18 where it is coupled to the input shaft 19 of a transmission 20 mounted on a base bracket 5a extending from one end of the tank 3. The output shaft 21 of the transmission 20 carries a sprocket 22 which is coplanar with the sprocket 23 secured to the mixing drum 7, and a sprocket chain 24 is disposed about the driving sprocket 22 and the driven sprocket 23 whereby the engine 14 through the drive shaft 17 and the transmission 20 drives or rotates the mixing drum 7.

The transmission 20 is connected with the base bracket 5a by bolts 25 in slotted holes. It is also connected with the top of the water tank 3 by adjustable braces 26. The transmission may be laterally adjusted by loosening the nuts on the bolts 25 and turning the adjustable braces 26, whereafter the nuts are again tightened on the bolts 25. The transmission may be laterally adjusted to insure proper tightness of the sprocket chain 24. The water tank 3 and transmission 20 thus constitute a sub-assembly extended transversely across te frame 2 which may be conveniently removed or replaced as a unit. The transmission 20 includes a shiftable member 27 for operating a clutch or change gear mechanism, the member 27 being pivoted at 28 to a lever 29 pivoted at 30 to the frame of the transmission. The opposite arm of the lever 29 is pivoted at 31 to an operating rod 32 which in turn is pivoted at 33 to a control handle 34. Both the drive shaft 17 and the operating rod 32 extend longitudinally of the frame alongside the mixing drum 7.

There is also mounted on the frame 2 at the same side as the engine 14 but at the forward portion thereof adjacent the transmission, a rotary pump 35 operated through a clutch and pulley 36 driven by a V-belt 37 from a pulley 38 carried by the element of the universal joint 18 which is connected with the transmission. Thus the engine 14 drives the pump 35 as well as the mixing drum 7.

A conduit 39 extends from the tank 3 to the intake of the pump 35. A conduit 40 extends from the pump outlet to the interior of the mixing drum 7. Thus water or other liquid may be pumped by the pump from the tank 3 to the interior of the mixing drum 7 either to form a component of the mixture or to flush out the mixing drum. As mentioned above, when the water is to form a component of the mixture the quantity of it introduced into the mixing drum is preferably measured by means well known in the art and not constituting the present invention. A sight gauge 41 indicates the level of the water in the tank 3. The pump 35 may be shifted on the carrier similarly to the transmission 20 to insure tightness of the belt 37.

The drawings show other elements of the truckmixer which are conventional and do not constitute the present invention and which therefore will not be described. Our invention is concerned with the novel arrangement of the elements referred to above whereby all of the massive parts of the mechanism are carried directly by the deck or chassis 2 in readily accessible positions. Moreover,

the arrangement is highly efiicient of space both horizontally and vertically and affords desired lateral balance. The center of gravity of the truckrnixer is unprecedentedly low, making for safety and enabling the vehicle to move at higher speeds over uneven terrain.

While we have shown and described a present preferred embodiment of the invention it is to be distinctly understood that the invention is not limited thereto but may be otherwise variously embodied within the scope of the following claims.

We claim:

l. A high-discharge truckmixer adapted to be mounted on a truck chassis with one end adjacent the truck cab and the opposite end at the rear of said chassis, comprising a mixing drum having a relatively large closed end I and a relatively small open end, a supporting frame below said drum adapted for supporting connection with said chassis in predetermined relation with the longitudinal axis of said chassis and in predetermined relation with the cab, a water tank mounted transversely across said frame at the cab end thereof, means for delivering liquid from said tank into said drum, means for rotatably mounting said drum in inclined position with the said closed end adjacent to and partially overhanging said water tank forwardly comprising a bearing on said tank and a pedestal within said tank, supporting rollers for carrying the upper open end of said drum, the axis of said drum being laterally eccentric of the longitudinal axis of said frame and chassis in the direction of the side of the mixing drum which moves downwardly when the drum is rotated in mixing direction, a transmission laterally adjacent an end of said tank and an engine laterally adjacent said drum, both said transmission and drum being on the other side of said longitudinal axis, means for rotatably driving said drum from said transmission, and torque-transmitting connections between said engine and said transmission, the eccentric and forward location of said drum distributing the load of the truckmixer when mixing substantially equally to the truck wheels on opposite sides and as evenly as practicable between rear and forward wheels of the truck.

2. In a truckmixer the improvement comprising in combination a water tank, a drum bearing and bearing pedestal, the said pedestal being within the confines of said tank and the said bearing being on the top of said tank and carried by said pedestal, a drum-supporting journal rotatably mounted in said bearing, a mixing drum having a closed end axially secured to and supported by said journal, one side of said tank being adjacent the closed end of said drum below the axis of the drum, the said axis of said drum and the said one side of the tank being oppositely inclined to the horizontal whereby said drum overlies a portion of said tank, and means for delivering liquid from said tank into said drum.

3. A truckmixer comprising a generally horizontal supporting frame, a mixing drum and a water tank, means for delivering liquid from said tank into said drum, the said water tank being mounted directly on said frame transversely across one end thereof at the extreme end of the frame, a bearing at the top of said tank, a journal extending from said mixing drum into said bearing for rotatably supporting one end of said drum, means erected from said frame for supporting the other end of said drum, and means for rotating said drum.

4. A truckmixer comprising a generally horizontal frame, a tank mounted directly upon the frame at one end thereof, a mixing drum mounted above the frame for rotation about an axis extending generally longitudinally of the frame, the mixing drum being disposed eccentrically of the frame to one side thereof, means including a hearing for rotatably mounting the mixing drum, means within the confines of the tank supporting the bearing, means for delivering liquid from the interior of the tank to the interior of the mixing drum and means mounted on the frame at the opposite side of the frame alongside the mixing drum for rotating the mixing drum.

5. A truckmixer comprising a generally horizontal frame, a tank mounted directly upon the frame at one end thereof, a mixing drum mounted above the frame for rotation about an axis extending generally longitudinally of the frame, the mixing drum being disposed eccentrically of the frame to one side thereof, means including a bearing for rotatably mounting the mixing drum, means within the confines of the tank supporting the bearing, a driving unit mounted on the frame alongside the mixing drum at the opposite side of the frame and at the other end of said frame, driving means extending from the driving unit longitudinally alongside the mixing drum, a connection from the driving means to the mixing drum for rotating the mixing drum, a pump, a conduit extending from the tank to the pump intake, a conduit extending from the pump outlet to the interior of the mixing drum and connections from the driving means to the pump for operating the pump.

6. A truckmixer comprising a generally horizontal supporting frame, a tank mounted directly upon the frame at one end thereof, a mixing drum mounted above the frame for rotation about an axis extending generally longitudinally of the frame, means including a bearing for rotatably mounting the mixing drum, means within the confines of the tank supporting the bearing, means for delivering liquid from the interior of the tank to the interior of the mixing drum, a driving unit mounted on the frame alongside the mixing drum at a side of the frame and at the other end thereof, a transmission connected with the mixing drum for rotating the mixing drum, the transmission being mounted on the frame forwardly of the driving unit, and a driving connection extending from the driving unit to the transmission alongside the mixing drum.

7. In a truckmixer having a generally horizontal supporting frame, a mixing drum and a water tank, the improvement comprising mounting said water tank directly on said frame transversely across one end of the frame, a supporting pedestal within said tank, a bearing above said tank supported by said pedestal, a journal axially secured in the mixing drum and projecting within said bearing for rotatably supporting said drum, means erected from said frame for supporting the other end of said drum, means for rotating said drum and means for discharging water from within said tank into said drum.

8. A high-discharge truckrnixer comprising a supporting frame adapted to be mounted on a truck chassis, a water tank directly mounted transversely across said frame at the extreme forward end thereof with respect to the truck on which the truckmixer is mounted, a mixing drum above said frame having a closed end facing the water tank, means for delivering liquid from said tank into said drum, means including a bearing at the top of said water tank for rotatably supporting the closed end of said drum, and means erected from said frame for rotatably supporting the other end of said drum, whereby the drum of said truckmixer is disposed forwardly on said frame and said truck.

9. In a truckmixer having a generally horizontal supporting frame, a water tank, a drum, means for delivering liquid from said tank into said drum, an engine and a transmission for rotating said drum, the improvement comprising in combination a water tank and transmission adjacently disposed transversely across one end of said frame with the water tank closer to said end, a bearing carried by the top of said tank, a journal axially projecting from the mixing drum over said tank into said hearing, a sprocket on said drum coaxial with said journal and adjacent said tank, a sprocket carried by said transmission co-planar with said first-mentioned sprocket, a chain belt engaging both said sprockets, adjustable means securing the top of said transmission to said tank adapted to move said transmission bodily to adjust the center distance between said sprockets, and driving connection between said transmission and said engine.

10. A truckmixer comprising a frame adapted to be mounted on a truck chassis including a pair of stringers whose common longitudinal center is the center-line of such chassis, a water tank extending between said stringers at one end thereof, a drum, means for delivering liquid from said tank into said drum, a bracket extending from one end of said tank laterally beyond the stringers, a transmission slidably mounted on said bracket, adjustablelength means connecting the top of said transmission to the end of said tank, a bearing rotatably mounting one end of said drum on the top of said tank, and a chainbelt drive from said transmission to said drum adjusted by bodily displacement of the transmission with respect to said hearing by adjusting said adjustable-length means.

References Cited in the file of this patent UNITED STATES PATENTS 1,862,999 Ball June 14, 1932 2,048,657 Jaeger July 21, 1936 2,318,293 Cornell May 4, 1943 2,556,034 Gerst June 5, 1951 2,624,557 Gerst Jan. 6, 1953 

